Sungrae Cho

Chung-Ang University · School of Computer Science and Engineering

In order to build realistic metaverse systems, enabling high synchronization between physical-space and virtual meta-space is essentially required. For this purpose, this paper proposes a novel system-wide coordination algorithm for high synchronization under characteristics ( i.e. , highly realistic meta-space construction under the constraints o...

This paper proposes a flexible and efficient access control scheme that combines the orthogonal frequency division multiple access and rate-splitting multiple-access techniques for enhancing the uplink transmission in a digital twin edge network system. We formulate a non-convex mixed integer optimization problem that minimizes the energy consumpti...

One of the essential factors for enabling sixth-generation systems is efficiently ensuring diverse quality-of-service (QoS) performance metrics to support the upcoming massive ultra-reliable low-latency communication (URLLC). This work proposes efficient transmission control in intelligent reflecting surface (IRS)-assisted nonorthogonal multiple ac...

Given the notable surge in Internet of Things (IoT) devices, low Earth orbit (LEO) satellites and unmanned aerial vehicles (UAVs) have emerged as promising networking components to supplement the network capacity and ensure seamless coverage in 6G, especially over remote areas. However, task offloading and resource management are challenging to rea...

The proliferation of Internet-of-Things applications has given rise to several challenges, including network congestion and high energy consumption. Among the promising technologies for beyond-5G networks, nonorthogonal multiple access (NOMA) and ambient backscatter communications stand out. These technologies enhance wireless access capacity and e...

Federated learning (FL) is a framework for realizing distributed machine learning in an environment where training samples are distributed to each device. Recently, FL has employed over-the-air computation enabling all devices to transmit learning model updates simultaneously. This work proposes a communication-efficient sparse one-bit analog aggre...

Compared to static time-division duplexing (TDD), dynamic TDD (D-TDD) has significantly increased the spectral efficiency of cellular networks. However, conventional systems operate based on exact channel state information, resulting in high communication overhead and delay. Spatial deep learning refers to using spatial geographical information as...

In the context of the Internet of Things (IoT), aerial computing platforms (ACPs) such as unmanned aerial vehicles and high-altitude platforms with edge computing capabilities have the potential to significantly expand coverage, enhance performance, and handle complex computational tasks for IoT devices (IoTDs). Non-orthogonal multiple access (NOMA...

Vehicle-to-everything (V2X) communication is an essential component for fully autonomous vehicles in future intelligent transportation systems, and cellular-V2X (C-V2X) is a standard that allows vehicles to communicate with its surroundings using cellular technology. Among the resource allocation modes of C-V2X, Mode 4 is a distributed scheme in wh...

Upscaling images typically depends on facial features, such as facial geometry details or references, to rebuild reasonable details. The low-quality input images cannot offer accurate geometric details, and the high-quality details are obscure, limiting performance in practical conditions. This work addresses the problem using an enhanced version o...

Resource management, security, and privacy stand as fundamental pillars for the reliable and secure operation of efficient semantic communications (SC) system. By addressing these aspects, SC system can pave the way for efficient resource utilization, improved network efficiency, enhanced communication performance, and protection of sensitive infor...

The exponential growth of the Internet of Multimedia Things (IoMT) traffic has posed a threat of service quality degradation due to the limitation of current communication, networking, and computing advances in mobile networks. In this regard, managing the Quality-of-Experience (QoE) for IoMT services is a vital challenge to meet user satisfaction....

This research aims to investigate a sum-rate maximization problem in uplink multi-user single-input multiple-output (SIMO) rate splitting multiple access (RSMA) systems. In these systems, Internet of Things devices (IoTDs) act as single-antenna nodes transmitting data to the multiple-antenna base station (BS) utilizing the RSMA technique. The optim...

In this study, we consider an energy-efficient and low-complexity transmission control in a SWIPT-NOMA-based green cellular network (GCN) that consists of a green base station (GBS) and green users (GUEs). First, we formulate a non-convex problem that minimizes transmit power consumption while supporting minimum downlink user service rate, downlink...

The recent expansion of mobile IoT devices (MIoTDs) along with the exposure of many compute-intensive and latency-critical applications, have given a step rise to the mobile edge computing (MEC) platform to process computational microservices at the edge. The paramount importance of designing an effective incentive mechanism is a very important top...

Recently, network coding has become a promising transmission approach to support high throughput and low latency in distributed multi-hop networks. In this paper, we develop a delay-controlled distributed route establishment scheme that can provide maximal bidirectional transmission to enhance network coding gain while satisfying a time-critical ro...

Rate-splitting multiple access (RSMA) and reconfigurable intelligent surface (RIS) techniques show promise in enhancing spectral efficiency in sixth-generation Internet of Things (IoT) networks. However, optimizing the synergy between these two methods is challenging due to the complex and dynamic environment. This study focuses on maximizing the s...

ate-splitting multiple access (RSMA) and reconfigurable intelligent surface (RIS) techniques show promise in enhancing spectral efficiency in sixth-generation Internet of Things (IoT) networks. However, optimizing the synergy between these two methods is challenging due to the complex and dynamic environment. This study focuses on maximizing the su...

As the cornerstone of IoT-based systems, WSN connecting a wide range of intelligent sensor nodes is expected to bring significant changesin the near future. Due to the limited battery capacity of the sensor node, WSN considers maximizing network lifetime by minimizing thepower consumption to be the most important challenge. To this end, we propose...

The synergy of uncrewed aerial vehicles (UAVs) and the rate-splitting multiple access (RSMA) technique has thrived as a crucial enabler for multi-user broadband sixth-generation networks. This paper investigates a UAV-aided RSMA downlink communication system considering user mobility and the uniform rectangular array antenna design. In particular,...

In recent years, we have witnessed a major expansion of wireless communications, extending from terrestrial to aerial spaces to facilitate novel user services. While aerial access infrastructure is widely accepted to be an essential part of a comprehensive sixth-generation (6G) network, underwater wireless communications (UWC), unfortunately, are n...

Unmanned aerial vehicles (UAVs) have been widely applied in wireless communications because of its high flexibility and line-of-sight transmission. In this study, we develop low-complexity and robust device-to-device (D2D) link scheduling in UAV-assisted industrial Internet of Things (IIoT) networks. First, we propose a sparse convolutional neural...

This article presents a delayed susceptibility, exposure, infectivity, recovery, and vaccination (SEIRV) model with nonlinear incidence and ratio-dependent functional responses. Model limitations and local stability analyses were examined with strict consideration of delay awareness. In addition, the presence of Hopf bifurcations with delay as a bi...

The emergence of novel mobile ecosystems such as mulsemedia and metaverse has encouraged the evolution of cloudification technologies to accommodate the increasing demand for user services with advanced in-network computing facilities. In this context, the development of privacy-sensitive heterogeneous hypercomputing (PSHH), a.k.a. the third genera...

The use of directional antennas in high-frequency bands (e.g., millimeter-wave) is essential to support applications requiring high throughput and low latency. However, communications using directional antennas require intricate scheduling by a central coordinator to avoid collision and deafness problems. Thus, in this study, we propose a direction...